Titanyl phthalocyanine crystal and electrophotographic photoreceptor using the same

Abstract

A novel titanyl phthalocyanine crystal, a photoconductive material comprising the same, and an electrophotographic photoreceptor using the same are disclosed. The titanyl phthalocyanine crystal has a primary particle diameter ranging from 0.03 to 0.15 μm, shows a maximum X-ray diffraction peak at a Bragg angle (2θ±0.2°) of 27.3°, has a ellipsoidal tabular form, and has a BET specific surface area of not less than 35 m 2 /g. The crystal has improved crystal form stability against solvents and holds its crystal form for an extended period of time in a dispersed and coated state. An electrophotographic photoreceptor using the crystal as a photoconductive material is excellent in sensitivity, stability, and durability.

What is claimed is:  
     
       1. An electrophotographic photoconductive material comprising a titanyl phthalocyanine crystal having a primary particle diameter ranging from 0.03 to 0.15 μm, showing a maximum X-ray diffraction peak at a Bragg angle (2θ±0.2°) of 27.30°, having a ellipsoidal tabular form, and having a BET specific surface area of not less than 35 m 2 /g. 
     
     
       2. An electrophotographic photoconductive material as claimed in claim  1 , wherein said crystal has an adsorbed water content ranging from 0.5% of its own weight to the saturated water adsorption at 20° C. and 40% RH. 
     
     
       3. An electrophotographic photoreceptor comprising a support having thereon a photosensitive layer comprising a binder resin having dispersed therein a titanyl phthalocyanine crystal having a primary particle diameter ranging from 0.03 to 0.15 μm, showing a maximum X-ray diffraction peak at a Bragg angle (2θ±0.2°) of 27.3°, having a ellipsoidal tabular form, and having a BET specific surface area of not less than 35 m 2 /g, said photosensitive layer showing a maximum X-ray diffraction peak at a Bragg angle (2θ±0.2°) of 27.3°.